Copolymers of beta-propionolactone



Patented Nov. 15, 1949 coroLYMERs or 2,487,885 BETA-PROPIONOLACTONE James E. Magoirln and Hugh J. Hagcmeyer, Jr., Kingsport, Tenn., assignors to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing. Application September 12, 1947,,

Serial No. 773,736

.14.Claims. 1

This invention relates to the preparation of new synthetic, resinous copolymers. More specifically this invention concerns a process for preparing resinous copolymers which comprises polymerizing a mixture of fl-propionolactone and an unsaturated organic compound.

It is known that p-propionolactone can be homopolymerized easily by heating in the presence or absence of a catalyst. Kung in U. S. Patent 2,361,036, dated October 24, 1944,-has shown that fl-propionolactone can be homopolymerized to form a linear polyester by heating the lactone with a Friedel-Crafts type catalyst or other condensation catalysts, such as potassium carbonate, sodium acetate, etc. in the presence of a solvent.

We have now found that new, resinous copolymers of p-propionolactone can be prepared by heating a mixture comprising p-propionolactone and a polymerizable unsaturated organic compound.

It is, therefore, an object of this invention to provide new synthetic copolymers of fl-propionolactone and an unsaturated organic compound.

A further object of this invention is to provide a process for preparing new, resinous copolymers of p-propionolactone and a polymerizable unsaturated organic compound. Other objects will become apparent from a consideration of the 4 following description.

According to our process, we prepare new,

resinous copolymers by heating a mixture comprising ,B-propionolactone and a polymerizable unsaturated organic compound.

The p-propionolactone which we use in our invention can be represented by the formula:

Kung in U. S. Patent 2,356,459, date August 22, 1944, shows a method of preparing ,B-propionolactone which comprises reacting ketene with formaldehyde in the presence of a Friedel-Crafts type catalyst. Another method is described in a copending application of Hugh J. Hagemeyer, Jr., Serial No. 660,287, filed April 5, 1946 now Patent No. 2,469,110. Surprisingly, it has been found that while other p-lactones, such as fl-butyrolactone, do not form copolymers with the unsaturated compounds employed in our invention, ,e-propionolactone forms copolymers with ease and yields products suitable for forming films, extruding into tubes, etc. This property of copolymerization of fl-propionolactones which is not shared by higher members of the p-lactone series. suggests some peculiar molecular rearrangement or orientation. However, the mechanism of the reaction has not been fully investigated.

The unsaturated, polymerizable organic compounds which we can conveniently employ in our invention contain the group j wherein Rrrepresents a hydrogen atom or a methyl group, and R2 represents an alkyl group such as methyl, ethyl, propyl, butyl, isobutyl, secondary and tertiary butyl (i. e., an alkyl group having the formula C1zH2n+1 where n is a positive integer from 1 to 4), an alkenyl group such as vinyl, allyl, methallyl, crotyl, (i. e., an alkenyl group having the formula CnH21i-1 where n is a positive integer from 2 to 4), or an aralkyl group such 'as benzyl, p-phenylethyl, ,c-phenylbutyl (i. e., an aralkyl group of the benzene series having 7 to 10 carbon atoms). Typical of the acrylates and methacrylates are: methyl acrylate, methyl c-methacrylate, ethyl acrylate, n-propyl, a-methacrylate, n-butyl a-methacrylate, benzyl acrylate, allyl a-methacrylate, methallyl acrylate, etc. In addition, the acrylates or methacrylates derived from the etherified or esterified derivativesorpoylhydric alcohols can be used. Ex-

amples of such esters are ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol acetate a-methacrylate, p-ethoxyethyl acrylate, p-butoxyethyl a-methacrylate, etc., i. e., the acrylates and methacrylates of polyvalent alcohols represented by the formula:

HO[CH (CH1).O (CH2) lCHzLOR;

where R: represents an alkyl group having the formula Cal-Ian where n is a positive integer mamas from 1 to 4, an acyl group such as acetyl, propionyl, butyryl, acryl, a-methacryl benzoyl,

toluoyl, etc. (i. e., an acyl radical of a mono basic carboxylic acid having .2 to 7 carbon atoms), and a, b, and c represent a positive integer from 1 to2.

wherein R4 and Rs represent the same or different groups as defined by Rs above. Typical esters are dimethyl maleate, dimethyl fumarate, diisopropyl fumarate, diethyl fumarate, diethyi maleate, dipropyl maleate, di-n-butyl fumarate, di-n-butyl maleate, dimethallyl maleate, dibenzyl i'umarate, etc. In addition, the simple or polyesters of polyvalent alcohols defined by the formula:

wherein Re, a, b, and e have the above definitions can be used. Typical of such esters are di-pethoxyethyl maleate, di-p-butoxyethyl fumarate, ethyl p-ethoxyethyl maleate, di-p-acetoxyethyl maleate, etc.

The vinyl esters which we can use may be represented by the formula:

wherein Ra represents an alkyl group such as methyl, ethyl, propyl, butyl, hexyl, octyl, nonyl, decyl, undecyl, tetradecyl, heptadecyl, etc., (i. e., an alkyl group of the formula CnHZrH-l. where n is a positive integer from 1 to 1'1) or an aryl group such as phenyl, chlorophenyl, m-, and p-tolyl. Typical are vinyl acetate, vinyl propionate, vinyl butyrate, vinyl oleate, vinyl benzoate, vinyl chlorobenzoate, -etc. In addition, the vinyl esters of dicarboxylic acids such as divinyl succinate, divinyl adipate, divinyl sebacate, divinyl phthalate, etc. can be used.

The alkyl alkenyl ketones which we can use may be represented by the formula:

0 Rr-tL-Rl wherein R1 is an alkyl group, such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, secondary and tertiary butyl (i. e., an alkyl group of the formula CnH2n+1 where n is a positive integer from 1 to 4) and Rs is an alkenyl radical such as vinyl, isopropenyl, allyl, methallyl, crotyl (i. e., an alkenyl group of the formula CnH2n-l where n is a positive integer from 2 to 4). Typical of such ketones are methyl, vinyl ketone, methyl isopropenyl ketone, ethyl isopropenyl ketone, etc. Other ketones such as divinyl ketone, diallyl ketone, etc. can also be used.

The acyloxy alkenyl nitriles which we can advantageously use can be represented by the formula:

CHFC-CN 0 II C--Rl wherein R9 represents an alkyl group, such as methyl, ethyl, propyl, isopropyl, butyl or isobutyl (i. e., an alkyl group having the formula CnHza-H where n is a positive integer from 1 to 4).

Typical are a-acetoxyacrylonitrile, a-propionoxyacrylonitrile, a-isobutyroxyacrylonitrile, etc.

The alkenyl nitriles which we can use can be represented by the formula:

wherein R11 represents a hydrogen atom or an allryl group, such as methyl, ethyl, (i. e., an alkyl group having the formula CnHflafl-i where n is a positive integer from 1 to 2) and R11 is a hydrogen atom or methyl group.. Typical are acrylonitrile, a-methacrylonitrile, 1-cyano-lpropene, and l-cyano-l-butene.

The hydrocarbons which we may use contain the group:

or a multiple thereof. Typical are the aliphatic diolefins such as butadiene-LS, isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, etc., the cycloaliphatic diolefins, such as cyclopentadiene, 1,3-cyclohexadiene, 2,2,1-bicycloheptadiene-1,3, etc., and aromatic olefins such as styrene, isopropenyl benzene, o-, m-, and pmethyl styrene, etc. Also vinyl acetylene, divinyl acetylene, etc., can be used.

In accordance with our invention we copolymerize p-propionolactone with one or more of the polymerlzable unsaturated organic compounds listed above. The copolymerization is accelerated by heat, and by the polymerization catalysts which are known to accelerate the polymerization of vinyl-type compounds. Exemplary of such catalysts are the organic peroxides (e. g., benzoyl peroxide, acetyl peroxide, benzoyl acetyl peroxide, lauroyl peroxide, etc.), hydrogen peroxide, perborates (e. g., alkali metal perborates) and persulfates (e. g., alkali metal persulfates).

The temperature at which the copolymerization is effected can vary from ordinary room temperatures (20-25 C.) to approximately 50 to C. The copolymerization can also be carried out by the head or emulsion method in which water or some other medium in which the monomers are insoluble is employed as a dispersing medium, with or without emulsifying agents. The emulsion method of copolymeriz'ation is particularly suitable where a large ratio of p-propionolactone to unsaturated organic compound is desired. The copolymerization can also be effected in the presence of a diluent, such as benzene, toluene, etc., which is advantageously a solvent for the copolymer.

Generally, any weight ratio of fi-propionolactone to unsaturated compound can be employed. Advantageously, we can use a ratio by weight of from 1:7 to 2:1 of fl-propionolactone to the unsaturated compounds (1. e., 1:2 parts by weight of p-propionolactone and 1:7 parts by weight of unsaturated compound can be used). If a relatively large ratio of p-propionolactone to unsaturated compounds has been used, the resulting product may be only slightly viscous or may consist of the copolymer dissolved in the excess of fl-lactone. To obtain the solid copolymer it is merely necessary to add a solvent to the reaction mixture which dissolves the excess }8 propionolactone but not the copolymer, thus precipitating the copolymer. Such solvents as methyl or ethyl alcohol are suitable for this purpose, although acetic acid, diethyl ether, etc., can also be used.

The following examples willserve to characterize our invention further.

. I 6 Example 1 Example I p-propionolactone and styrene, in the amounts 1 In the manner identical to that described in given in the tabulation below, were copolymerlzed Example 1, p-propionolactone and methyl at 50 C.' using 0.20-396 by weight, based on the methacrylate were copolymerized. The results total weight of the reaction mixture. or a 4% 5 obtained wereasiollows:

r o 1 m m w 1 m M 1 l on Lecgme e Rgtio 1211210 Remarks Gram Cram:

7-2 10 l/l medium, hard, clear, colorless. l 10 ll].

g. 6 i3 5..-. 1/2 hard, clear, colorless. 7.2 6 27i soit, clear, colorless, suriace 10 2/1 hardening.

solution of acetyl peroxide in dimethyl phthalate Example 5 as catalyst. The polymerization took place fi-propionolactone gms.) and methyl vinyl smoothly and was complete in 24 hours. The ketone (10 gms.) were copolymerized by heating results obtained were as follows: at 40 C. for 48 hours in the presence of 0.06%

"1 28.82? some 25? tilt Grams Grams 4 8 l/2 8/11 hard clear, colorless. 4 12 1/3 l 2 150. a 12 1 4 me Do. 2 10 l/5 4/15 hard, clear, surface erasing. 2 12 1/6 1/4 hard, clear, colorless. 2 14 1 1 l/5 Do.

Example 2 by weight, based on the total weight of the rep-propionolactone and methyl acrylate, in the acgiogmifture of ai fi i A resin soft amounts given in the tabulation below were copa 8 was e polymerized by heating in sealed tubes in the Example 6 presence of 0.05%, by weight, based on the total weight of the reaction mixture of a 4% solution B-propionolactone and a-acetoxy acrylonitrile,

of acetyl peroxide in dimethyl phthalate as cata- 1n the weight ratios given be o were 1 3 lyst. The temperature was maintained at 45 C. 40 merized by heating at 60 C. in the presence of by means of a constant temperature water bath 0.05% by weight, based on the total weight of the so that efficient heat transfer may be obtained. reaction mixture, of a 4% acetyl peroxide solu- Usually the heating required an induction period tion in dimethyl p fl e esu ts btained of several hours, after which the polymerization are as follows:

took place rapidly and to completion. The 00- polymers thus obtained had rubber-like prop- Weight ratio of p'promonolactone erties, and showed good elasticity and low to acrylonltrue: Remarks strength. Surface hardening was efiected by 1/1 hard, clear, dark brown resin heating at -100 C. in the presence of air. The 1/2 Do. results obtained were as follows: 50 1/3 Do.

-P 1 Mthl W'ht Ml. lia t gz t l Acsyla te Rit io Ratio Remarks Grams Grams 7.2 8.6 l/l Soft, clear, colorless, low 10 10 1/1 strength.

2. 6 3. 6 ""17 1/2 hard rubber, clear, colorless. 7.2 4.3 ill soft, clear, colorless, low 10 5 2/1 strength.

Example 3 Emmpk 7 ,B-propionolactone and diisopropyl fumarate, This example illustrates the emulsion method in the weight ratios given below, were copolyof preparing the resins O our invention s. merized by heating at 45 c. with 0.05% by 200 r ms of methylm thacrylat 72 rams of weight, based on the total weight of the reaction fi-Dropionolactone, gram of gum arabic. and mixture, of a 4% acetyl peroxide solution in 1 gram of acetyl peroxide i di ethyl phthadimethyl phthalate as catalyst. The results oblate were dispersed i 0 1- f distilled water.

mined follow; and then agitated at 45 C. for 24 hours. Clear, 1

l 1 Weight ratio of ,B-propionolactone fggg jggf bgads were obtained in 89% yield t ii propyl fumarate! Remarks Other unsaturated polymerizable organic com- 1/2 Hard, opaque resin pounds can replace those illustrated in the above 1/1 Do. examples. Other valuable resins can be prepared 2/1 Do. 7 by heating p-propionolactone and ethylene glycol oneness diacrylate, p-propionolactone and cyclopentadiene, p-propionolactone and methyl isopropenyl ketone, etc.

The synthetic resins and elastomers obtained according to the process of our invention are suitable for molding compositions, production of sheets, films, foils, etc.

We claim:

1. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolacione and from 1 to 7 parts by weight of styrene.

2. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of methyl a-methaorylate.

3. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of an alkyl alkenyl ketone represented by the formula:

wherein R is an alkyl radical having the formula cnH2n+1 wherein n is a positive integer from 1 to 4 and R1 is an alkenyl radical having the formula CnH2n-1 wherein n is a positive integer from 2 to 4.

4. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolactone and from 1 to '7 parts by weight of methyl vinyl ketone.

5. A process for preparing a resinous copolymer which comprises polymerizing in the presence of a peroxide polymerization catalyst a mixture consisting of 1 to 2 parts by weight of fl-propionolactone and 1 to 7 parts by weight of an alkyl alkenyl ketone having the formula:

R( ,Ri wherein R. represents an alkyl group having the formula C1|H2n+i wherein n is a positive integer from 1 to 4 and R1 represents an alkenyl group having the formula Camp-1 wherein n is a positive integer from 2 to 4.

6. A process for preparing a resinous copolymer which comprises polymerizing in the presence of a peroxide poLymei-ization catalyst a mixture consisting of from 1 to 2 parts by weight of p-propionolactone and 1 to 2 parts by weight of methyl a-methacrylate.

'7. A process for preparing a resinous copolymer which comprises polymerizing in the presence of a peroxide polymerization catalyst a mixture consisting of l to 2 parts by-weight of fi-propionolactone and 1 to 7 parts by weight of methyl vinyl ketone.

8. A process for preparing a resinous copolymer which comprises polymerizing in the presence of a peroxide polymerization catalyst a mixture con- 8 sisting of 1 to 2 parts by weight of p-mmomlactone and 1 to 7 parts by weight of styrene.

9. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of a compound containing a 'polymerizable --CH=C group, prior to the polymerization.

10. A resinous copolymer obtainedby polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of a compound containing a polymerizable group, prior to the polymerization.

11. A resinous copolymer obtained by polymerizing in the presence of a peroxide polymerization catalyst a mixture comprising from 1 to 2 parts by weight of s-propionolactone and from 1 to '7 parts by weight of an ester selected from those represented by the following general formula:

wherein R2 represents an alkyl group having the formula C1|H2n+1 wherein n is a positive integer from 1 to 4.

12. A process for preparing a resinous copolymer comprising polymerizing from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of a compound containing a polymerizable ,CH=C

group in the presence of a peroxide polymerization catalyst.

13. A process for preparing a resinous copolymer comprising polymerizing from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts bzlweight of a. compound containing a polymeriza e CH2=C group in the presence of a peroxide polymerization catalyst.

14. A process for preparing a resinous copolymer comprising polymerizing from 1 to 2 parts by weight of p-propionolactone and from 1 to 7 parts by weight of an ester selected from those represented by the following general formula:

CH2=C-(J-OR wherein R2 represents an alkyl group having the formula CnH2n+l wherein n is a positive integer from 1 to 4 in the presence of a peroxide polymerization catalyst.

JAMES E. MAGOFFIN. HUGH J. HAGEM'EYER, JR.

No references cited. 

